Thickening of solutions



tented .lan. fi i943 THICKENING F SOLUTIONS Morris Batman and Frank J.Calm, Chicago, BL,

assign-101's to The Emulsol ,Corporation, Chico, M1.

N0 Drawing. Application y 16, 19M,

Serial No. 393,845

16 'Elaims.

This invention relates to the thickening of detergent solutions and isparticularly concerned with the thickening of shampoos comprisingaqueous solutions of anionic interface modifying agents having goodlathering and detergent properties.

In dealing with detergent solutions of interface modifying agents whichare known to the prior art, it frequently becomes highly desirable toincrease the thickness, consistency or viscosity of said solutions. Asan example, preparations have been produced in accordance with prior artteachings wherein an interface modifying agent having sudsing anddetergent powers is dissolved in a suitable solvent such as water ororganic solvents such as alcohol or aqueous-organic solvents such asmixtures of water and alcohol. For meeting the demands of certainclasses of trade, it is highly advisable to provide a product having arelatively heavy consistency or an enhanced thickness. While an increasein thickening may, in certain cases, be accomplished by increasing theconcentration of the interface modifying agent in its solvent, thisbecomes impracticable in most cases since the interface modifying agentsare frequently soluble to only a limited extent in the particularsolvent preferred to be used. In addition, the increase in theconcentration of the interface modifying agents, aside from otherdisadvantages emanating from such practice, is usually uneconomic sincethe degree of enhancement of thickness or increase in viscosityattainable by such method is insufficient to warrant the substantiallgreater cost involved.

Solutions, for example, aqueous solutions, containing as high as ormore, by weight, of some interface modifying agents are almost as limpidas water. When poured from a bottle and handled, there is a markedtendency for loss of solution by spilling.. It becomes highlyadvantageous in many instances to increase the thickness, consistency orviscosity of such and similar solutions to facilitate the handlingthereof and minimize the loss during pouring and the like from bottlesor similar containers or receptacles. Other advantages accrue from thepresent invention into which it is not necessary to go into detail.

It is, accordingly, an important object of the present invention toincrease thickness or viscosity of solutions of interface modifyingagents in a relatively simple and inexpensive manner.

A further object of the invention is to increase the thickness orviscosity of shampoos comprising aqueous solutions of interfacemodifying agents which have high sudsing and detergent properties.

Other objects and features of the invention will become apparent as thedetailed description of the invention proceeds.

As a result of considerable research work, a

large class of thickening agents has been discovered of general utilityfor thickening solutions of interface modifiers, and of marked utilityfor thickening solutions, particularly aqueous solutions, of interfacemodifying agents having good sudsing and detergent properties. Thesethickeners may be characterized as certain partial esters of aliphaticpolyhydric alcohols or allphatic polyhydroxy substances. Particularlyuseful are the caprylic acid mono-esters of diethylene glycol andtriethylene glycol, and of unusual utility is the caprylic acidmono-ester of triethanolamine hydrochloride.

The aliphatic polyhydroxy substances whose partial esters comprise thethickening agents utilized in accordance with the present invention maybe selected from a large group including, among those previouslymentioned, glycerol; glycols such as ethylene glycol, propylene glycol,trimethylene glycol, butylene glycol and the like; polyglycols such asdiethylene glycol, triethylene glycol, and tetraethylene glycol;pentaerythritol; quercitol; di-hydroxy acetone; polyglycerols such asdiglycerol, triglycerol, tetraglyceroi and the like including mixturesthereof; carbohydrates and sugars including mono-, diand polysaccharidessuch as dextrose, sucrose, xylose, arabinose, galactose, fructose,maltose, mannose, and the like; the natural and synthetic simple andcomplex glucosides; sugar alcohols such as arabitol, mannitol, mannitan,sorbitol, sorbitan, and dulcitol; and polyhydroxy-carboxylic acids suchas tartaric acid, 'mucic acid, saccharic acid, gluconic acid, glucuronicacid, gulonic acid, mannom'c acid, trihydroxyglutaric acid, glycerlcacid, carboxylic oxidation products of polyglycerols, others of similarcharacter, and hydroxyethyl and hydroxypropyl ether derivatives of theabove, as, for example:

(For convenience, all hydroxyl groups are written facing one way.)

Still others are triethanolamlne, tripropanolamine,tri-isopropanolamine, tributanolamine, tripentanolamine,trihexanolamine, monoethanol dipropanolamine, diethanolmono-propanolamine, monoethanol monobutanolamine, diethanolmonobutanolamine; l-amino-2,3 -propanediol; 2- amino-1,3-propanediol;2-amino-2 methyl 1,3- propanediol; trimethylol-amino methane;Z-amino-Z-n-propyl-1,3-propanediol;2-amino-2-3-isopropyl-1,3-propanediol; 2-amino-2-ethylol 1,3-propanediol; trimethylol amino methyl methane; alkylol polyamines suchas alkylol derivatives of ethylene diamine, diethylene triamine, andtriethylene tetra-amine as, for example, di (hydroxy-ethyl) ethylenediamine; polyhydroxy amino-carboxylic acids; hydroxy tertiary aminesderived from other polyhydric alcohols, including glycols, sugars andsugar alcohols such as ethylene glycol, diethylene glycol, dextrose,sucrose, sorbitol, mannitol and dulcitol;

and the like. Polymerized hydroxy tertiary amines prepared, for example,by polymerizing triethanolamine or other hydromr tertiary amines such asthose mentioned hereinabove, particularly in the presence of a catalystsuch as sodium hydroxide or the like, may also be employed. Thepreparationof polymerized hydroxy tertiary amines is disclosed, forexample, in United States Patent No. 2,178,173. Homologues substitutionderivatives of theabove-mentioned hydroxy amines may also be utilized.

It will be understood that the aliyphatic polyhydrow substances may beutilized in pure, im-

or commercial form.

The aliphatic acids which are esterifled with the aliphatic polyhydroxysubstances to form the thickening agents may be selected from a largegroup including straight chain and branched chain, saturated andunsaturated, carboxylic, aliphatic, cycloaliphatic, and fatty acids,including caproic acid, enanthic acid, caprylic acid, pelargonic acid,capric acid, sebacic acid, behenic acid, arachidic acid, lauric acid,myris'tic acid, mixtures of any two or more of the above mentioned acidsor other acids; hydroxy and alpba-hydroxy higher carboxylic aliphaticand fatty acids such as alpha-hydroxy capric acid, alpha-hydroxy lauricacid, alpha-hydroxy myristic acid, alphahydroxy coconut oil mixed fattyacids, and the like. It will be understood that mixtures of any two ormore of said acids may be employed if desired. The acids may be employedas such or in the form of their anhydrides, esters including mono-, di-,tri-glycerides and the like,,and acyl halides, or, in general, in theform of any of their acylating compounds. Of particular utility are theunsubstituted fatty acids containing from six to ten carbon atoms andtheir acyl halides.

The thickening agents should be soluble in the solutions of theinterface modifying agents. In

molecule of the compounds themselves.

acorns"? As illustrative of thickeners falling within the scope of theinvention may be mentioned, by way of example, in addition to thosepreviously referred to, Z-ethyl hexoic acid mono-ester oftriethanolamine hydrochloride; caproic acid monoester oftripropanolamine acetate; capric acid mono-ester of tributanolaminehydrochloride; enanthic acid mono-ester of diethylene glycol; pelargonicacid mono-ester of tetraethylene glycol, and the like.

It is convenient to prepare a solution of the thickener and add it inthe desired amounts to the interface modifying agent solution althoughthe manner of incorporation is optional and may be accomplished invarious ways, as, for example, in certain cases, in situ during thepreparation of the solution of the interface modifying agent. Since, inthe main, aqueous solutions of interface modifiers are employed, thethickeners utilized in such solutions will be water-soluble. It will beunderstood that in all cases the thickener must be soluble in thesolution of the interface modifier in which it is employed.

The anionic interface modifying agents whose solutions may be thickenedby means of the compounds disclosed hereinabove are generallycharacterized by the presence of at least one higher molecular weightlipophile group containing preferably at least eight carbon atoms,preferably although not necessarily, aliphatic in character, and by thepresence of at least one hydrophile or hydrophillic group. preferably inthe form of an oxygenated sulphur, phosphorus or boron radical,particularly sulphur in the form of sulphate or sulphonic acid radicals,although, as will be seen, the hydrophillic group is not so limited.Preferabh', the lipophile and hydrophile groups are in a state ofbalance whereby the resulting compound has the property of reducing thespattering of margarine when used for frying. This concept of balance oflipophile and hydrophile groups is treated in considerable detail in thepatent to Benjamin R. Harris, No. 1,917,250, isssued July 11, 1933, andneed not here be elaborated upon further. While this "balance may bedetermined empirically by means of a margarine frying test, as describedin said patent, those skilled in the art will, in most cases, readily beable to predict the existence of balance" from merely an inspection ofthe As a general rule, the hydrophile and lipophile groups shouldpreferably be at the ends or extremities of the molecule as, forexample, in the case of lauryl sodium sulphate wherein the lauryl group,or, in other words, the lipophile group, is present at one end of themolecule, and the sulphate or hydrophile group is present at the otherend of the molecule.

As previously indicated, the invention is particularly useful withrespect to the thickening of solutions of those interface modliyingagents which have good sudsing, foaming and detergent properties. Thisaspect of the invention will become more apparent as the descriptionproceeds.

It will be understood that the term lipophile group" includes groupshaving a definite alfinity for oils and fats and comprises, for example,alkyl, aralkyl, aryl, ether or ester groups containing "preferably atleast eight carbon atoms. The lipophile group possessespredominantly'hydrocarbon characteristics and, in general, is derivedfrom triglyceride fats and oils, waxes, mineral oils, otherhydrocarbons. and the like.

asoaoer in contra-distinction thereto, the term hydrophile group orhydrophillic group" includes groups which possess an amnity for waterand aqueous media. As examples of such groups may be mentioned thefollowing: hydroxyl, hydroxylcarboxylic, sulphate, sulphonic, phosphate,pyrophosphate, tetraphosphate, borate, lower molecular weightsulpho-carboxylic acids such as sulphoacetates, sulphopropionates,sulphosuccinates, sulphoglutarates, and the like.

Among the interface modifying agents whose solutions may be thickened inaccordance with the present invention are organic substances havingbalanced lipophile and hydrophile groups, the lipophile group containingat least eight carbon atoms and the hydrophile group comprising aradical selected from the class consisting of oxygenated sulphur,oxygenated phosphorus, and oxygenated boron inorganic acid radicals.

One sub-class thereof, several members ofwhlch have excellent sudsing,foaming, frothing, lathering, and detergent powers, comprises the highermolecular weight alcohol sulphates and sulphonates. The alcohols fromwhich these sulphates and sulphonates may be prepared include thefollowing: aliphatic straight chain and branched chain alcohols such asoctyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, laurylalcohol, myristyl alcohol, cetyl alcohol, oleyl alcohol, llnoleylalcohol, stearyl alcohol, ricinoleyl alcohol, palmitoleyl alcohol,melissyl alcohol, ceryl alcohol, carnaubyl alcohol, myricyl acohol,branched chain octyl, decyl, dodecyl, tetradecyl, hexadecyl andoctadecyl aliphatic alcohols as, for example, 2-ethyl hexanol-l, 2-nbutyl octanol-l, Z-butyl tet'radecanol-Land, in general, the highermolecular weight saturated and unsaturated aliphatic straight chain andbranched chain alcohols. Preferably, the alcohols which are utilized arethose corresponding to the fatty acids occurring in triglyceride oilsand fats of vegetable or animal origin, natural or hydrogenated, such ascorn oil, cottonseed oil, sesame oil, coconutoil, palm kernel oil,sunflower seed oil, lard, tallow, soya bean oil and the like, thosealcohols containing from 12 to 18 carbon atoms being preferred. Otheralcohols which may be employed are the cycle-aliphatic or all-cyclicalcohols such as the sterols, as, for example, cholesterol,iso-cholesterol, phytosterol, sitosterol, hydroaromatic alcohols such asabietol, and such unsaturated alcohols as llnalol, citronellol, geranioland the like. Also included within the class of alcohols which may beemployed are such compounds as the hydroxy and alpha-hydroxy higheraliphatic and fatty acids as, for example, ricinoleic acid, alphahydroxystearic acid, alpha-hydrow lauric acid, di-hydroiw stearic acid,i-hydroxystearic acid, alpha-hydroxy palmitic acid, and the like, aswell as esters of hydroxy-fatty acids, such as ethyl rlcinoleate, castoroil, butyl alpha-hydroxystearate, cetyl hydroxystearate, and the like.

The term alcohols" as employed herein, is intended to include alcoholswhich may or may not contain other groups such as carboxylic, halogen,sulphonic, sulphate, or other radicals. The alcohols obtainable bysubstituting alkyl or acyl radicals, preferably of high molecularweight, in place of the hydrogen of one or more hydroxy groups ofpolyhydroxy substances or polyhydric alcohols, it being understood thatat least one hydroxy group attached to the nucleus of the polyhydroxysubstance or polyhydric alcohol remains, are also within the scope ofthe alcohols sulphates and sulphonates may be produced. As examples ofsuch alcohols may be mentioned pan tially esterified or partiallyetherified sugars and sugar alcohols such as monolauric acid ester ofsucrose, monostearic acid ester of dextrose, monopalmitic acid ester ofmannitol, dicaproic acid ester of maltose, monooctyl ether of sorbitol,monolauryl ether of pentaerythritol, monolauric acid ester ofpentaerythritol, and the like; the monoglycerides and diglycerides,preferably of the higher fatty acids, as, for example, monolaurln,monornyristin, monostearin, distearin, diolein, dicaproin, mono-laurylether of glycerol, di-cetyl ether of glycerol, monostearic acid ester ofdiethylene glycol, monolauric acid ester of ethylene glycol, and thelike.

It is, of course, obvious that the alcohols from which the sulphates andsulphonates may be produced may be prepared in accordance with anydesired method. For example, many of these alcohols may be prepared bythe so-called Bouveault and Blank method or, alternatively, by thereduction or catalytic reduction with hydrogen of natural orhydrogenated animal or vegetable fats and oils, or mixtures thereof, inaccordance with well known practices. Again the alcohols may be derivedfrom synthetic processes such as by the oxidation of hydrocarbons or maybe prepared by saponifieation of waxes and the like. Alternatively, theymay be prepared by reduction of aldehydes or by the Grignard reaction.

It is likewise apparent that mixtures of the foregoing or other alcoholsmay be utilized in the preparation of the sulphates and sulphonates as,for example, the mixture of alcohols resulting from the hydrogenation ofcoconut oil or the free fatty acids of coconut oil. Lauryl alcoholcomprises about 45% of the total alcohol mixture, the remaining alcoholsrunning from Co to C13. Again, mixtures of alcohols such as are presentin the socalled sperm oil alcohols, as well as those present inwool-fat, may equally efllcaciously be utilized. Indeed, these highermolecular weight alcohols are generally offered on the market in theform of mixture of different alcohols. If desired, for any specificpurpose, special fractions which predominate in a certain particularhigher molecular weight alcohol may be utilized or, if so desired, theproducts may be prepared from a single, substantially pure alcohol.

These sulphates and sulphonates, described hereinabove, may, in general,be represented by the formula wherein R represents the residue of anormal primary alcoholcontaining from 8 to 18 carbon atoms, Y representsa cation or the residue of a salt-forming compound such as sodium,triethfrom which the fitanolamlne or the like, and n is a small wholenumber, at least one.

The sulphates and sulphonates described are preferably utilized in theform of salts and, in

their preparation, the acid sulphuric ester or sulphonic acid may beneutralized, in whole or in part, with suitable anti-acid materials. Inthis connection, considerable latitude and modification may beexercised. In general, inorganic as well as organic anti-acid agents maybe employed. Examples of such agents which may be used satisfactorilyare bicarbonates of the alkali metals, potassium hydroxide, sodiumoxide, sodium carbonate, ammonium hydroxide, ammonia gas, potassiumstearate, sodium stearate, magnesium oxide, magnesium carbonate, organicanti-acid nitrogenous materials including amines and alkylolamines suchas, for example, mono-, diand triethanolamine and mixtures thereof,propanolamines, butanolamines, polynitrogenous amines such as ethylenediamlne, ethylene triamine and the like, pyridine, piperidine,quaternary ammonium bases such as tetraethyl ammonium hydroxide,tetra-methyl ammonium hydroxide, and in general, primary, secondary andtertiary amines substituted or not with other radicals such as hydroxygroups, and the like. It will be understood that by the term cation, asused throughout the specification and claims, is meant hydrogen and suchother element as are mentioned herein, and, in general. atoms orradicals which are regarded 'as bearing a positive charge or capable ofreplacing acidic hydrogen. The reaction products may be neutralized tomethyl orange, litmus or phenolphthalein. As a general rule, if thesalts of the reaction products are employed, it is preferred to use thesodium, potassium, ammonium, triethanolamine. quaternary ammonium, orother relatively highly soluble salts.

The sulphates and sulphonates disclosed hereinabove are described, amongother places, in the following United States Patents 1,897,741;1,968,793; 1,968,794; 1,968,796; 1,968,797; 2,006,309; 2,023,387;2,028,091; 2,052,027, and 2,077,005.

Another sub-class of interface modifying agents whose solutions may bethickened are those compounds which correspond to the higher molecularweight alcohol sulphates and sulphonates described hereinabove butwherein the hydrophile group comprises oxygenated phosphorus instead ofoxygenated sulphur. Among these compounds may be mentioned laurylpyrophosphate, palmityl orthophosphate, sodium lauryl tetraphosphate,stearyl triethanolamine orthophosphate, oleyl monoethanolaminepyrophosphate, monolauric acid ester of diethylene glycoltetraphosphate, monoethanolamine salt, and the like. As in the case ofthe sulphates and sulphonates described previously, it is generallypreferred to employ the oxygenated phosphorus derivatives in the form oftheir alkali, ammonium, or nitrogenous base or alkylolamine salts. Thesecompounds are disclosed, among other places, in the following UnitedStates Patents 2,026,785; 2,052,029; 2,053,653; 2,128,946, and2,177,650.

Again, in place of either the oxygenated phosphorus or oxygenatedsulphur compounds, similar as well as corresponding oxygenated boroncompounds may be employed. These include boric acid esters of highermolecular weight alcohols such as lauryl borate, cetyl borate, and boricacid esters of monoglycerides of higher fatty acids such as monostearinborate. For a more complete description of such or similar compounds,reference may be made to United States Patent No. 2,052,192.

Another class of interface modifying agents whose solutions may bethickened in accordance with the principles of the present invention arethe lower molecular weight sulphocarboxylic acid esters of highermolecular weight alcohols such as those described hereinabove. Amongthese compoundsmay. e mentioned the monoethanolamine or triethanolaminesalts or other highly soluble salts of octyl sulphoacetate, laurylsulphoacetate, cetyl sulphoacetate, and the like. For a more completedescription of such compounds, reference may be had to the followingUnited States Patents Nos. 1,917,250; 2,166,141; 2,166,142; 2,166,143,and 2,185,455; and British Patent No. 377,249.

Another class of interface modifying agents whose solutions may beeffectively thickened in accordance with the teachings of the presentinvention are the salts, such as the alkali metal salts, of thesulphoacetates of halogenated lauryl alcohol, as disclosed in theapplication of Benjamin R. Harris et al., Serial No. 308,578, filedDecember 11, 1939, now Patent No. 2,251,932, issued August 12, 1941. 7

Still another class of interface modifying agents whose solutions may bethickened in ac- -cordance with the teachings of the present inventionare the compounds which correspond to the general formulae or the like,and w is a small whole number. As illustrative of these compounds may bementioned the following:

1 7, W at These compounds and others of similar nature are disclosed inthe following United States Patents 1,981,792; 1,931,540; 1,932,177, and1,932,180.

It will be understood that the radical R in the above general formulaemay be derived from higher aliphatic, fatty, cycloaliphatic, aromatic,and hydroaromatic acids such as the following: saturated and unsaturatedhigher molecular weight aliphatic acids such as the higher fatty acidscontaining at least eight carbon atoms and including caprylic acid,pelargonic acid, caprlc acid, melissic acid, stearic acid, oleic acid,ricinoleic acid, linoleic acid, linolenic acid, lauric acid, myristicacid, palmitic acid, mixtures of any two or more of the above mentionedacids, or other acids, mixed higher fatty acids derived from animal orvegetable sources, for example, lard, coconut oil, sesame oil, corn oil,cottonseed oil, sardine oil, tallow, partially or completelyhydrogenated animal and vegetable oils such as those mentioned; hydroxyand alpha-hydroxy higher aliphatic and fatty acids such as i-hydroxystearic acid, dihydroxystearic acid, alphahydroxy stearic acid,alpha-hydroxy palmitic acid, alpha-hydroxy lauric acid, alpha-hydroxycoconut oil mixed fatty acids, and the like; aliphatic acids derivedfrom various waxes such as beeswax, spermaceti, montan wax, and camaubawax and higher molecular, weight carboxylic acids derived, by oxidationand other methods, from petroleum; hydroaromatic acids such as abieticacid; aromatic acids such as naphthoic acid, hydroxy aromatic acids suchas hydroxy naphthoic acids, and the like.

Another class of sulphur-containing interface modifying agents thethickening of whose solutions may be effected in accordance with theteachings of the present invention comprises those compounds whichcorrespond, in general, to the formula Z--OX -S-X=-Y wherein X and Xrepresent members selected from the class consisting of alkylene andsubstituted alkylene groups, Z represents a lipophillic group, and Yrepresents a hydrophillic group such as hydroxyl, sulphate, sulphonic,phosphate,

phosphonic, and the like. Illustrative of such compounds are thefollowing:

oiwgenated phosphorus. Examples of such compounds are as follows:

may be thickened in accordance with the present invention are thosedisclosed in United States Patent No. 2,184,770. At least most of thecompounds disclosed in said patent correspond to the following generalformula:

wherein 0 at is an aliphatic acyl radical containing at least eightcarbon atoms, alk is hydrocarbon, Y is a member selected from the groupconsisting of hydrogen, alkyl, cycloalkyl, alkoxyl, aralkyl, aryl,

and alkylol, Z. is a hydrocarbon residue, and X is a sulphonic group.

Additional groups of compounds which may be thickened by means of theprocess of the present invention include those which are disclosed inUnited States Patents Nos. 2,176,896; 2,178,139; 2,198,806; 2,236,528;2,236,529, and in the following copending applications:

Morris Katzmanet a1 286, 776 July 27, 1939 Morris Katzman--." $6, uly27,1939 Morris Katzman et a1... 291, 898 ug. 25, 1930 -Albert K. E steinat al 919 Sept. 28, 1939 Frank J. C natal Nov. 28,1939

Representative compounds disclosed in said pat- 5 ents and applications,whose salts, and especially whose organic nitrogenous base salts may beI thickened in accordance with the process of the It will, of course, beappreciated that the various thickening agents vary in their potency.Tha

p se invention, p se t o n amount to be employed will accordingly bedetermined not only by this fact but also will be a dependent upon thespecific character and concentration of the interface modifying agent in(b) C"Hitl-C-NH-ClHl-O-fi-CE:- OIH.NE(CI IOH)x the solution thereof, andthe particular results desired.

0 While, as stated and as is obvious, the amount O W of thickener whichmay be employed is variable i (c) CaHr-O- CuHn within relatively wideranges of proportions, in

order to indicate the remarkable and unusual aspects of this phase ofthe invention, the following facts should be understood. Aqueoussolutions it of the thickening agents, or substantially all of the same,which are disclosed herein, even in concentrations as high as 50% wherethey are solu- O ble to such an extent, are of a very limpid char-CnHarC-NH-CaHc-NH-C-CHz-CH-CO0K acter with viscosity practicallyidentical with or OHBNHMIOH), as not much greater than that of ordinarywater.

Nevertheless, the addition of relatively small proportions of suchlimpid solutions to interface modifying agent solutions results in anentirely unexpected increase in thickness and viscosity 2% of saidlatter solutions. That this happens in the face of and notwithstandingthe mutual dilution which simultaneously occurs is all the moreremarkable. The following table illustrates the nature of the resultswhich have been '30 obtained:

Interface modifier solution Addition agent Result]! 2 g. caprylic acidConsiderable in mono-eater of crease in vis- (i) 100 g. of a 17% aqumcuaaolution oi monocthanolamine salt of triothanolocosity.

mine.

acidified with 1 g. tartaric acid. (2) 100 g. of a 17% aqueous aolutionoi monoethanolsmins salt of 8 g. caprylic acid Do.

mono-ester of diothylene glycol.

(t) 100 g. of a 17% aqueous solution or! monocthanolsmine salt of 3 hg.01f Z-ethIyJ Do.

exo e no C Hm-GO-CzHr-NHCHaBOaH mono-ester of triothanolamine.

acidified with 1.5 g. tartaric acid. (4) 100 g. of a 3102, aqueousaolution of tristhauolomins salt of lauryl sulphate acidified with 2. g.4 g. caprylic acid Do.

tartaricaci mono-ester of triethanola- (5) cc. of a 10% aqueous solutionof tristhauolaminc salt of lam'yi oulphoacotato 1.5 enanthio Substantialinaci monocster crews in viaoli til'iothylono coaity.

' i! 57 (6) 10 cc. of a aqueous aolution oi ixicthanolamino salt oilauryl aulphtatc 1.8 g. pelargonic Appreciablc thiclracid mono-eatersuing. Elf diethylono YOO (7) 10 cc. of a 25% aqueous solution oftricthanolamhio salt of lauryl sulphate E. mouocapry- Do.

(a) 10 cc. of a ii0% aqueous aolntion of iaopropylnaphthalenosulphonaie, sodium salt 0.5 t. of hydro- Do.

chloride of caprylic acid mono-cater oi triothanolamine.

0 H o 0 It will be understood that, by the selection of (m c I certainthickeners and certain interface modi- W hers, and by varying theproportions or concen- CIHP'O C CHT-SOIH-HINC!-HOH trations thereof, theincrease in thickness or viscosity can be readily controlled to anydesired value. The thickening agent is utilized in proportionssubstantially less than the proportions of the interface modifyingagent, in the usual case from 5% to 20% thereof. In general, it ispreferred to increase the thickness or viscosity of the interfacemodifying agent solutions by at least several fold, preferably a minimumof fivefold and usually at least ten-foldto fifty-fold.

- thereto a substantially is it is preferred to carry out the inventionwith respect to the thickening of aqueous solutions of the interfacemodifying agents, it must not be inferred that the invention is solimited. Alcohols or other organic solvents may be employed, as well asaqueous-organic solvent mixtures, but for economic and other obviousreasons water is preferred.

The term solution" as employed herein and in the appended claims isemployed in a broad sense to include not only true solutions but alsocolloidal dispersions.-

The term higher, as employed herein, is intended to mean not less thaneight carbon atoms and, concomitantly, the term lower will be understoodto mean less than eight carbon atoms, unless otherwise specificallystated.

The terms interface modifier and interface modifying agent, are employedinterchangeably herein and are intended to embrace substances whichcomprise lipophile and hydrophilegroups and which are capable ofreducing surface and interfacial tension, other than soaps or salts suchas alkali metal salts of higher fatty acids.

While the thickening effect increases, in general, with increasingconcentrations of interface modifying agents, it commences to becomeappreciable, in most cases, at concentrations of the order of magnitudeof five to ten percent. The invention is, therefore, particularlyapplicable in connection with concentrations of interface modifiers ofthis order of magnitude and substantially beyond the above-mentionedrange. Indeed, the invention is applicable to the treatment of solutionsof interface modifiers of as high as or strength, or even higher.

What we claim as new and desire to coveriby Letters Patent of the UnitedStates is:

Lil

l. A method of thickening a solution of at least 5% of an anionicinterface modifier having a lipophile group with at least eight carbonatoms and a hydrophile group, which comprises adding thereto asubstantially lesser proportion of an aliphatic partial ester of analiphatic polyhydroxy substance, which ester is soluble in saidsolution, sumcient to appreciably thicken the same.

2. A method of thickening a solution of at least 5% of an anionicinterface modifier having a lipcphiie group with at least eight carbonatoms and a hydrophile group, which comprises adding lesser proportionof a fatty acid mono-ester of an aliphatic polyhydroxy substance, thefatty acid radical oi which contains from 6 to 10 carbon atoms, whichester is soluble in said solution, suflicient to appreciably thicken thesame.

3. A'method of thickening a solution of at least 5% of an anionicinterface modifier having a lipophile group with at least eight carbonatoms and a hydrophile group, which comprises adding thereto asubstantially lesser proportion of a fatty acid mono-ester of anhydroxy-alkyl tertiary amine, which ester is soluble in said solution,sumcient toappreciably thicken the same.

i. A method of thickening a solution of at least 5% of an anionicinterface modifier having a lipophile group with at-least eight carbonatoms and a hydrophile group, which comprises adding thereto asubstantially lesser proportion of a caprylic acid mono-ester oftriethanolamine, which ester is soluble in said solution, sufficient toappreciably thicken the same.

5. A method of thickening an aqueous solution of at least 5% of ananionic interface modifier with-at least eight carhaving a lipophilegroup bon atoms and a hydrophile group, which comprises adding thereto aproportion of a caprylic acid mono-ester of diethylene glycol,suificient to appreciably thicken the same.

6. A substantially clear solution of at least 5% of an alkyl sulphatehaving at least eight carbon atoms, containing a substantially lesserproporlion of an aliphatic partial ester of an aliphatic polyhydroxysubstance, which ester is soluble in said solution, sufiicientto-appreciably thicken the same.

7. A substantially clear solutionof at least 5% of an organicnitrogenous base salt of a sulphuric acid ester of an aliphatic alcoholhaving from eight to eighteen .carbon atoms and containing asubstantially lesser proportion of a fatty acid mono-ester of analiphatic polyhydroxy substance, the fatty acid radical of whichcontains from 6 to 10 carbon atoms, which ester is soluble in saidsolution, sufilcient to appreciably thicken the same.

8. A substantially clear solution of at least 5% of an alkylolamine saltof a sulphuric acid ester of a straight chain aliphatic alcohol havingfrom eight to eighteen carbon atoms and containing a small proportion ofa caprylic acid mono-ester of diethylene glycol, which ester is solublein said solution, sufli'cient to appreciably thicken the same.

9. A substantially clear aqueous solution of at least 5% of analkylolamine salt of lauryl sulphate and containing a substantiallylesser proportion of ,a caprylic acid mono-ester of triethanolamine,which ester is soluble in said solution, sufl'icient to appreciablythicken the same.

10. An aqueous solution of at least 5% of an alkylolamine salt of thesulphuric acid ester of a mixture of alcohols derived from cocoanut oiland comprising predominantly lauryl alcohol, and containing asubstantially lesser proportion of a partial ester of a fatty acid witha watersoluble polyhydric alcohol, the fatty acid radical containingfrom 6 to 10 carbon atoms, which ester is soluble in said solution,suiflcient to appreciably thicken the same.

11. A solution'of at least 5% of an anionic interface modifying agentfalling into the caten e-04pm wherein R is an aliphati hydrocarbonradical containing at least 7 carbon atoms and preferably between 11 and17 carbon atoms, X is hydrogen, n is zero or one, Y is a lower molecularweight hydrocarbon radical, M is an oxygenated sulphur-containinginorganic acid radical, and w is a small whole number, and containing asmall proportion of an aliphatic partial ester of an aliphaticpolyhydroxy substance, which ester is soluble in said solution,sufllcient to appreciably thicken the same. 12. An aqueous solutioninterface modi formulae R-o -0 clms oz of at least 5% of an ying agenthaving the general wherein taining 12 to 18 carbon atoms, and Z is acation, and containing a small proportion of a partial ester of analiphatic polyhydroxy substance with a fatty acid containing from 6 to10 carbon atoms, which ester is soluble in said solution, sufficient toappreciably thicken-the same.

13. An aqueous solution of at least of an alkylolamine salt of ananionic interface modifier having a iipophile group with at least eightcarbon atoms and an oxygenated sulphur hydrophile group, said solutioncontaining a substantially lesser proportion of a water-solublemonoester of a fatty acid with an aliphatic water-soluble polyhydroxysubstance, which ester is soluble in said solution, sumcient toappreciably thicken the same.

14. An aqueous solution of at least 5% of a salt of a chemical compoundcorresponding to the general formula wherein R is an organic radicalcontaining at least eight carbon atoms, all: and Z are eachmembers'selected from the class consisting of hydrocarbon radicals andsubstitution products thereof, Y is a member selected from the groupconsisting of hydrogen, allryl and allrylol, m and w are whole numbers,and X is a sulphonic acid with an aliphatic polyhydroxy substance,

the fatty acid radical of which contains from 6 to 10 carbon atoms,which ester is soluble in said solution, suificient to appreciablythicken the same.

15. An aqueous solution of at least 5% of a monoethanolamine salt of thesulphoacetic acid amide of the lauric acid ester of monoethanolamine,and containing a small proportion of a fatty acid mono-ester with aglycol, the fatty acid radical of which contains from 6 to 10 carbonatoms, which ester is soluble in said solution, sufilcient toappreciably thicken the same.

16. An aqueous solution of at least 5% of a monoethanolamine salt of thesulphoacetic acid amide Of the lauric acid ester of monoethanolamine,and containing a small proportion of a caprylic acid mono-ester oftriethanolamine, sumcient to appreciably thicken the same.

MORRIS KATZMAN. FRANK J. CAHN.

